Controllable waveform terahertz generation using rippled plasma driven by an inhomogeneous electrostatic field

We theoretically present thewaveformcontrols of terahertz (THz) radiations generated from homogeneous and rippled plasma within inhomogeneous external electrostatic field. The Particle-in-cell (PIC) simulations is implemented to demonstrate generation and controllability of three types of THz pulses: single frequency THz pulse in homogeneous plasma, broadband THz pulse and dual frequency THz pulse in rippled plasma. The single frequency THz pulse can be tuned via shifting the knob of electron density of homogeneous plasma. Waveform of broadband THz pulse can be regulated into an envelope-like shape by varying amplitude of electron density of rippled plasma. The two center frequencies' interval of dual frequency THz pulse can be controlled by wave numbers of density distribution of rippled plasma. This work provides a potential means to generate the dual frequency THz pulses with two harmonic frequencies (omega+Omega omega, Omega=2) or incommensurate frequencies (omega+Omega omega, Omega=1.7,1.8, 2.2...). (c) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

In this paper, we theoretically propose a method to control the waveform of terahertz (THz) radiations generated from homogeneous and rippled plasma within an inhomogeneous external electrostatic field. Particle-in-cell (PIC) simulations are used to demonstrate the generation and controllability of three types of THz pulses: single frequency THz pulse in homogeneous plasma, broadband THz pulse, and dual frequency THz pulse in rippled plasma. The parameters of the pulses can be adjusted by manipulating the electron density of the plasma, allowing for tunable THz pulses with different characteristics.